The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a well system with screened valves for selective well stimulation and control.
Several systems have been used in the past for selectively fracturing individual zones in a well. In one such system, a coiled tubing string is used to open and close valves in a casing string. In another system, balls are dropped into the casing string and pressure is applied to shift sleeves of valves in the casing string.
It will be appreciated that use of coiled tubing and balls dropped into the casing string obstruct the interior of the casing string. This reduces the flow area available for pumping stimulation fluids into the zone. Where the stimulation fluid includes an abrasive proppant, ball seats will likely be eroded by the fluid flow.
Furthermore, these prior systems do not include any means for preventing proppant, formation fines, etc. from flowing into the casing string after a stimulation operation has been concluded, for example, during testing, completion or production operations.
Therefore, it may be seen that improvements are needed in the art of selectively stimulating and controlling flow in a well.